U.S. Pat. No. 6,891,762 discloses displays in which the light output for each pixel is determined by two signals. In some embodiments, one signal controls the light transmission of a first light modulator and a second signal controls the intensity of the light that is incident on a part of the light modulator that corresponds to the pixel. The second signal may control directly a light source, such as a light emitting diode (LED) that illuminates a portion of the first light modulator, or may control a modulator located between a light source and the first light modulator.
There is a need for electronic displays that are reliable and cost-efficient to manufacture and repair. There is a particular need for such displays that can provide high dynamic ranges. Such needs exist for both projection-type displays and displays that have an integrated screen.